fwu: metadata: add functions for handling version specific metadata fields

Support is being added in U-Boot for version 2 of the FWU
metadata. Support for this version is to co-exist with version 1
support. To achieve this, a common, version agnostic structure has
been added to keep information provided by the FWU metadata
structure.

Add API's to handle the version specific FWU metadata fields. The
version agnostic structure gets initialized at boot by reading the FWU
metadata. Updates to the FWU metadata result in the API's getting
called to populate the version specific fields of the strucure, before
the metadata gets written to the storage media.

Signed-off-by: Sughosh Ganu <sughosh.ganu@linaro.org>
Tested-by: Michal Simek <michal.simek@amd.com>
diff --git a/lib/fwu_updates/fwu_v1.c b/lib/fwu_updates/fwu_v1.c
new file mode 100644
index 0000000..efb8d51
--- /dev/null
+++ b/lib/fwu_updates/fwu_v1.c
@@ -0,0 +1,167 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2024, Linaro Limited
+ */
+
+#include <fwu.h>
+#include <fwu_mdata.h>
+
+#include <linux/types.h>
+
+#define FWU_MDATA_VERSION	0x1U
+
+static uint32_t fwu_check_trial_state(struct fwu_mdata *mdata, uint32_t bank)
+{
+	u32 i;
+	struct fwu_image_entry *img_entry;
+	struct fwu_image_bank_info *img_bank_info;
+
+	img_entry = &mdata->img_entry[0];
+	for (i = 0; i < CONFIG_FWU_NUM_IMAGES_PER_BANK; i++) {
+		img_bank_info = &img_entry[i].img_bank_info[bank];
+		if (!img_bank_info->accepted) {
+			return 1;
+		}
+	}
+
+	return 0;
+}
+
+static void fwu_data_init(void)
+{
+	size_t image_info_size;
+	void *dst_img_info, *src_img_info;
+	struct fwu_data *data = fwu_get_data();
+	struct fwu_mdata *mdata = data->fwu_mdata;
+
+	data->crc32 = mdata->crc32;
+	data->version = mdata->version;
+	data->active_index = mdata->active_index;
+	data->previous_active_index = mdata->previous_active_index;
+
+	data->metadata_size = sizeof(struct fwu_mdata);
+	data->num_banks = CONFIG_FWU_NUM_BANKS;
+	data->num_images = CONFIG_FWU_NUM_IMAGES_PER_BANK;
+	fwu_plat_get_bootidx(&data->boot_index);
+	data->trial_state = fwu_check_trial_state(mdata, data->boot_index);
+
+	src_img_info = &mdata->img_entry[0];
+	dst_img_info = &data->fwu_images[0];
+	image_info_size = sizeof(data->fwu_images);
+
+	memcpy(dst_img_info, src_img_info, image_info_size);
+}
+
+static int fwu_trial_state_update(bool trial_state)
+{
+	int ret;
+	struct fwu_data *data = fwu_get_data();
+
+	if (trial_state) {
+		ret = fwu_trial_state_ctr_start();
+		if (ret)
+			return ret;
+	}
+
+	data->trial_state = trial_state;
+
+	return 0;
+}
+
+/**
+ * fwu_populate_mdata_image_info() - Populate the image information
+ * of the metadata
+ * @data: Version agnostic FWU metadata information
+ *
+ * Populate the image information in the FWU metadata by copying it
+ * from the version agnostic structure. This is done before the
+ * metadata gets written to the storage media.
+ *
+ * Return: None
+ */
+void fwu_populate_mdata_image_info(struct fwu_data *data)
+{
+	size_t image_info_size;
+	void *dst_img_info, *src_img_info;
+	struct fwu_mdata *mdata = data->fwu_mdata;
+
+	image_info_size = sizeof(data->fwu_images);
+	dst_img_info = &mdata->img_entry[0];
+	src_img_info = &data->fwu_images[0];
+
+	memcpy(dst_img_info, src_img_info, image_info_size);
+}
+
+/**
+ * fwu_state_machine_updates() - Update FWU state of the platform
+ * @trial_state: Is platform transitioning into Trial State
+ * @update_index: Bank number to which images have been updated
+ *
+ * On successful completion of updates, transition the platform to
+ * either Trial State or Regular State.
+ *
+ * To transition the platform to Trial State, start the
+ * TrialStateCtr counter, followed by setting the value of bank_state
+ * field of the metadata to Valid state(applicable only in version 2
+ * of metadata).
+ *
+ * In case, the platform is to transition directly to Regular State,
+ * update the bank_state field of the metadata to Accepted
+ * state(applicable only in version 2 of metadata).
+ *
+ * Return: 0 if OK, -ve on error
+ */
+int fwu_state_machine_updates(bool trial_state,
+			      __maybe_unused uint32_t update_index)
+{
+	return fwu_trial_state_update(trial_state);
+}
+
+/**
+ * fwu_get_mdata_size() - Get the FWU metadata size
+ * @mdata_size: Size of the metadata structure
+ *
+ * Get the size of the FWU metadata.
+ *
+ * Return: 0 if OK, -ve on error
+ */
+int fwu_get_mdata_size(uint32_t *mdata_size)
+{
+	*mdata_size = sizeof(struct fwu_mdata);
+
+	return 0;
+}
+
+/**
+ * fwu_init() - FWU specific initialisations
+ *
+ * Carry out some FWU specific initialisations including allocation
+ * of memory for the metadata copies, and reading the FWU metadata
+ * copies into the allocated memory. The metadata fields are then
+ * copied into a version agnostic structure.
+ *
+ * Return: 0 if OK, -ve on error
+ */
+int fwu_init(void)
+{
+	int ret;
+	uint32_t mdata_size;
+
+	fwu_get_mdata_size(&mdata_size);
+
+	ret = fwu_mdata_copies_allocate(mdata_size);
+	if (ret)
+		return ret;
+
+	/*
+	 * Now read the entire structure, both copies, and
+	 * validate that the copies.
+	 */
+	ret = fwu_get_mdata(NULL);
+	if (ret)
+		return ret;
+
+	fwu_data_init();
+
+	return 0;
+}